In circulatory system that circulates bloods in body, efficiencies and forms of blood circulation have a close relation with circulatory diseases. For example, a circulatory system with low efficiency stresses the heart, which increases a risk of heart failure. The efficiency of blood circulation can be described by momentum or energy of blood.
Not only regarding heart but also in blood vessel disease such as arteriosclerosis, it has become apparent that a shear stress describing a kinetic exchange between a blood vessel and a blood flow when the blood flows is closely concerned with diseases (Non Patent Literature 1).
In order to examine circulation efficiency or blood flow dynamic state of a circulatory tissue, it is required to acquire the mechanistic mutual relation between the circulatory tissue and the blood flow. In order to achieve it, it is required to quantitatively calculate the circulatory tissue motion and the blood flow vector around the boundary between the circulatory tissue and the blood flow, and to digitize its effects to analyze them.
Patent Literature 1 listed below describes a method for calculating a blood flow vector by integrating a plurality of differential images.